U.S. patent application number 15/534572 was filed with the patent office on 2017-11-30 for curable organopolysiloxane composition, cured product thereof, and method for forming cured film.
This patent application is currently assigned to Dow Corning Toray Co., Ltd.. The applicant listed for this patent is Dow Corning Toray Co., Ltd.. Invention is credited to Takuya OGAWA, Satoshi ONODERA.
Application Number | 20170342198 15/534572 |
Document ID | / |
Family ID | 56126213 |
Filed Date | 2017-11-30 |
United States Patent
Application |
20170342198 |
Kind Code |
A1 |
OGAWA; Takuya ; et
al. |
November 30, 2017 |
CURABLE ORGANOPOLYSILOXANE COMPOSITION, CURED PRODUCT THEREOF, AND
METHOD FOR FORMING CURED FILM
Abstract
A curable organopolysiloxane composition comprises: (A) an epoxy
group-containing organopolysiloxane represented by the average
composition formula: X.sub.aR.sup.1.sub.bSiO.sub.(4-a-b)/2 wherein
X represents at least one type of epoxy group selected from a
glycidoxyalky group, an epoxycycloalkyl alkyl group, and an
epoxyalkyl group; R.sup.1 represents a hydrogen atom, an alkyl
group, an alkenyl group, an aryl group, an aralkyl group,a hydroxyl
group, or an alkoxy group; provided at least two X groups are
present in a molecule; and "a" and "b" are numbers satisfying:
0<a<1, 0<b<3, and 0.8<a+b<3; (B) a compound
having at least two mercapto groups in a molecule; and (C) an amine
compound not having a N--H bond and/or a phosphine compound not
having a P--H bond. The composition has favorable curability even
at a relatively low temperature, and forms a cured film having
excellent bonding with regard to an object to be coated.
Inventors: |
OGAWA; Takuya; (Chiba,
JP) ; ONODERA; Satoshi; (Chiba, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dow Corning Toray Co., Ltd. |
Tokyo |
|
JP |
|
|
Assignee: |
Dow Corning Toray Co., Ltd.
Tokyo
JP
|
Family ID: |
56126213 |
Appl. No.: |
15/534572 |
Filed: |
December 4, 2015 |
PCT Filed: |
December 4, 2015 |
PCT NO: |
PCT/JP2015/006050 |
371 Date: |
June 9, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08G 59/66 20130101;
C09D 183/06 20130101; C09D 7/40 20180101; C08L 83/08 20130101; C08K
5/17 20130101; C08G 77/14 20130101; C08K 5/49 20130101; C09D 183/08
20130101; C08G 77/28 20130101; C08L 83/06 20130101; C09D 183/06
20130101; C08L 83/00 20130101 |
International
Class: |
C08G 59/66 20060101
C08G059/66; C09D 183/06 20060101 C09D183/06; C09D 7/12 20060101
C09D007/12; C08L 83/06 20060101 C08L083/06; C08K 5/17 20060101
C08K005/17; C08K 5/49 20060101 C08K005/49; C09D 183/08 20060101
C09D183/08; C08L 83/08 20060101 C08L083/08 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 18, 2014 |
JP |
2014-256077 |
Claims
1. A curable organopolysiloxane composition comprising: (A) an
epoxy group-containing organopolysiloxane represented by the
average composition formula: X.sub.aR.sup.1.sub.bSiO.sub.(4-a-b)/2
wherein X represents at least one type of epoxy group selected from
the group consisting of a glycidoxyalkyl group, an epoxycycloalkyl
alkyl group, and an epoxyalkyl group; R.sup.1 represents a hydrogen
atom, an alkyl group with 1 to 12 carbon atoms, an alkenyl group
with 2 to 12 carbon atoms, an aryl group with 6 to 20 carbon atoms,
an aralkyl group with 7 to 20 carbon atoms, a hydroxyl group, or an
alkoxy group with 1 to 6 carbon atoms; provided at least two X
groups are present in a molecule; and "a" and "b" are numbers
satisfying: 0<a<1, 0<b<3, and 0.8<a+b<3; (B) a
compound having at least two mercapto groups in a molecule, in an
amount such that mercapto groups in component (B) per 1 mol of the
epoxy group in component (A) are 0.3 to 3 mols; and (C) an amine
compound not having a N--H bond and/or a phosphine compound not
having a P--H bond, in an amount of 0.01 to 10 mass % per the total
amount of components (A) through (C).
2. The curable organopolysiloxane composition according to claim 1,
wherein component (B) is: (B1) a mercapto group-containing
organopolysiloxane represented by the average composition formula:
Y.sub.cR.sup.2.sub.dSiO.sub.(4-c-d)/2 wherein Y represents at least
one type of mercapto group selected from the group consisting of a
mercaptoalkyl group and a mercaptoaryl group; R.sup.2 represents a
hydrogen atom, an alkyl group with 1 to 12 carbon atoms, an alkenyl
group with 2 to 12 carbon atoms, an aryl group with 6 to 20 carbon
atoms, an aralkyl group with 7 to 20 carbon atoms, a hydroxyl
group, or an alkoxy group with 1 to 6 carbon atoms; provided at
least two Y groups are present in a molecule; and "c" and "d"
represent numbers satisfying: 0<c<1, 0<d<3, and
0.8<c+d<3; and/or (B2) a thiol compound having at least two
mercapto groups in a molecule.
3. The curable organopolysiloxane composition according to claim 1,
wherein component (C) is a tertiary amine compound.
4. The curable organopolysiloxane composition according to claim 1,
further comprising: (D) an organic solvent in an amount of from
greater than 0 to 3,000 parts by mass per a total of 100 parts by
mass of components (A) through (C).
5. The curable organopolysiloxane composition according to claim 1,
further defined as a coating composition.
6. A cured product formed by curing the curable organopolysiloxane
composition according to claim 1.
7. A method for forming a cured film, the method comprising the
steps of: coating a curable organopolysiloxane composition onto an
object to be coated; and curing the curable organopolysiloxane
composition at -5 to 30.degree. C.; wherein the curable
organopolysiloxane composition is according to claim 5.
8. The curable organopolysiloxane composition according to claim 2,
wherein component (C) is a tertiary amine compound.
9. The curable organopolysiloxane composition according to claim 2,
further comprising: (D) an organic solvent in an amount of from
greater than 0 to 3,000 parts by mass per a total of 100 parts by
mass of components (A) through (C).
10. The curable organopolysiloxane composition according to claim
3, further comprising: (D) an organic solvent in an amount of from
greater than 0 to 3,000 parts by mass per a total of 100 parts by
mass of components (A) through (C).
11. The curable organopolysiloxane composition according to claim
2, wherein component (B) is component (B1).
12. The curable organopolysiloxane composition according to claim
2, wherein component (B) is component (B2).
13. The curable organopolysiloxane composition according to claim
1, wherein component (C) is the amine compound not having a N--H
bond.
14. The curable organopolysiloxane composition according to claim
1, wherein component (C) is the phosphine compound not having a
P--H bond.
Description
TECHNICAL FIELD
[0001] The present invention relates to a curable
organopolysiloxane composition, a cured product thereof, and a
method for forming a cured film using the composition.
BACKGROUND ART
[0002] Curable organopolysiloxane compositions are cured to form
cured products with excellent adhesion, bonding, weather
resistance, and electrical properties, and therefore, the
compositions are used in adhesives, sealing agents, coating agents,
and the like in electrical or electronic parts. For example, patent
document 1 proposes a curable organopolysiloxane composition
comprising an epoxy group-containing organopolysiloxane, and a
curing agent or curing catalyst; and patent document 2 proposes a
curable organopolysiloxane composition comprising an epoxy
group-containing organopolysiloxane, a straight chain
organopolysiloxane having at least two phenolic hydroxyl groups,
and a curing accelerator. However, this type of curable
organopolysiloxane composition must be heated to 150.degree. C. to
cure, and thus quickly curing at a relatively low temperature of
30.degree. C. or lower is difficult.
[0003] In recent years, a curable organopolysiloxane composition
comprising, as a main agent, an epoxy group-containing
organopolysiloxane, has been examined for application in paint
compositions. When considering use of paint compositions outdoors
during the winter, quick curing at 30.degree. C. or lower is
required. Therefore, a curable organopolysiloxane composition
having favorable curability even at a relatively low temperature is
required.
PRIOR ART DOCUMENTS
Patent Documents
[0004] Patent Document 1: Japanese Unexamined Patent Application
Publication No. H05-320514
[0005] Patent Document 2: Japanese Unexamined Patent Application
Publication No. 2005-154766
OVERVIEW OF THE INVENTION
Problem to be Solved by the Invention
[0006] An object of the present invention is to provide: a curable
organopolysiloxane composition having favorable curability even at
a relatively low temperature of 30.degree. C. or lower, and that
forms a cured film with excellent bonding with regard to an object
to be coated; and a cured product with excellent bonding with
regard to an object to be coated. Furthermore, another object of
the present invention is to provide a method for forming a cured
film at a relatively low temperature.
SUMMARY OF THE INVENTION
[0007] A curable organopolysiloxane composition of the present
invention comprises:
[0008] (A) an epoxy group-containing organopolysiloxane represented
by the average composition formula:
X.sub.aR.sup.1.sub.bSiO.sub.(4-a-b)/2
[0009] wherein, X represents at least one type of epoxy group
selected from a group consisting of a glycidoxyalkyl group, an
epoxycycloalkyl alkyl group, and an epoxyalkyl group; R.sup.1
represents a hydrogen atom, alkyl group with 1 to 12 carbon atoms,
alkenyl group with 2 to 12 carbon atoms, aryl group with 6 to 20
carbon atoms, aralkyl group with 7 to 20 carbon atoms, hydroxyl
group, or alkoxy group with 1 to 6 carbon atoms; however, at least
two X are present in a molecule; and "a" and "b" are numbers
satisfying: 0<a<1, 0<b<3, and 0.8<a+b<3;
[0010] (B) a compound having at least two mercapto groups in a
molecule, in an amount such that mercapto groups in component (B)
per 1 mol of the epoxy group in component (A) are 0.3 to 3 mols;
and
[0011] (C) an amine compound not having a N--H bond and/or a
phosphine compound not having a P--H bond, in an amount of 0.01 to
10 mass % per the total amount of components (A) through (C).
[0012] A cured product of the present invention is formed by curing
the aforementioned curable organopolysiloxane composition.
[0013] A method of forming a cured film of the present invention
includes steps of: coating the curable organopolysiloxane
composition onto an object to be coated; and performing curing at
-5 to 30.degree. C.
Advantageous Effects of the Invention
[0014] The curable organopolysiloxane composition of the present
invention has favorable curability at a relatively low temperature,
and can form a cured film with excellent bonding with regard to an
object to be coated. Furthermore, a method for forming a cured film
of the present invention can quickly cure the curable
organopolysiloxane composition at a relatively low temperature.
DESCRIPTION OF EMBODIMENTS
[0015] A curable organopolysiloxane composition of the present
invention is described below in detail.
[0016] An epoxy group-containing organopolysiloxane of component
(A) is a main component of the present composition, and is
represented by the average composition formula:
X.sub.aR.sup.1.sub.bSiO.sub.(4-a-b)/2
[0017] In the formula, X represents at least one type of epoxy
group selected from the group consisting of a glycidoxyalkyl group,
an epoxycycloalkyl alkyl group, and an epoxyalkyl group. Examples
of the glycidoxyalkyl groups include 2-glycidoxyethyl groups,
3-glycidoxypropyl groups, and 4-glycidoxybutyl groups. Examples of
the epoxycycloalkyl alkyl groups include
2-(3,4-epoxycyclohexyl)ethyl groups and
3-(3,4-epoxycyclohexyl)propyl groups. Examples of the epoxyalkyl
groups include 2,3-epoxypropyl groups, 3,4-epoxybutyl groups, and
4,5-epoxypentyl groups. Component (A) has at least two epoxy groups
(X) in a molecule.
[0018] Furthermore, in the formula, R.sup.1 represents a hydrogen
atom, alkyl group with 1 to 12 carbon atoms, alkenyl group with 2
to 12 carbon atoms, aryl group with 6 to 20 carbon atoms, aralkyl
group with 7 to 20 carbon atoms, hydroxyl group, or alkoxy group
with 1 to 6 carbon atoms. Examples of the alkyl group include a
methyl group, ethyl group, propyl group, butyl group, pentyl group,
hexyl group, heptyl group, octyl group, nonyl group, decyl group,
undecyl group, and dodecyl group, but a methyl group is preferred
from the perspective of economic efficiency and heat resistance.
Examples of the alkenyl group include a vinyl group, allyl group,
butenyl group, pentenyl group, hexenyl group, heptenyl group,
octenyl group, nonenyl group, decenyl group, undecenyl group, and
dodecenyl group, but a vinyl group, allyl group, hexenyl group, and
octenyl group are preferred from the perspective of economic
efficiency and reactivity. Examples of the aryl group include a
phenyl group, tolyl group, xylyl group, naphthyl group, biphenyl
group, and phenoxyphenyl group, but phenyl groups, tolyl groups,
and naphthyl groups are preferred from the perspective of economic
efficiency. In particular, by introducing an aryl group, and
particularly a phenyl group into the organopolysiloxane of
component (A), compatibility with component (B) tends to improve
and weather resistance of an obtained cured product tends to
improve. Examples of the aralkyl group include a benzyl group,
phenethyl group, and methylphenylmethyl group. Further examples
include groups where a portion of or all of the hydrogen atoms
bonded to the alkyl group, alkenyl group, aryl group, or aralkyl
group are substituted by a chlorine atom, bromine atom, or other
halogen atom. Examples of the alkoxy group include a methoxy group,
ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group,
sec-butoxy group, and tert-butoxy group. R.sup.1 may have two or
more types of the aforementioned groups.
[0019] Furthermore, in the formula, "a" is a number that indicates
a ratio of epoxy groups to silicon atoms, and satisfies
0<a<1, and preferably 0<a.ltoreq.0.6, or
0<a.ltoreq.0.4. Furthermore, in the formula, "b" is a number
that indicates a ratio of hydrogen atoms, alkyl groups with 1 to 12
carbon atoms, alkenyl groups with 2 to 12 carbon atoms, aryl groups
with 6 to 20 carbon atoms, aralkyl groups with 7 to 20 carbon
atoms, hydroxyl groups, or alkoxy groups with 1 to 6 carbon atoms
with regard to silicon atoms, and satisfies 0<b<3. However,
the total of "a" and "b" is a number that satisfies:
0.8<a+b<3, and preferably 1<a+b.ltoreq.2.2, or
1<a+b.ltoreq.2.0. This is because when "a" is a number within
the aforementioned range, the curability of the obtained curable
organopolysiloxane composition at a relatively low temperature is
favorable, and the mechanical strength of the obtained cured
product is favorable. This is also because when "b" is a number
within the aforementioned range, the mechanical strength of a cured
product improves. Furthermore, when the total of "a" and "b" is a
number within the aforementioned range, the curability of the
obtained curable organopolysiloxane composition at a relatively low
temperature is favorable, and the mechanical strength of the
obtained cured product is favorable.
[0020] The molecular weight of component (A) is not particularly
restricted, but the weight average molecular weight measured by gel
permeation chromatography is preferably 1,000 or more and 50,000 or
less. This is because when the weight average molecular weight of
component (A) is equal to or greater than the lower limit of the
aforementioned range, the mechanical properties of the obtained
cured product are favorable, and when equal to or less than the
upper limit of the aforementioned range, the curing rate of the
obtained curable organopolysiloxane composition improves.
[0021] Examples of component (A) include one type or a mixture of
two or more types of an organopolysiloxane as represented by the
following average unit formulas. Note that in the formulas, Me, Ph,
Vi, Ep, and Ep' respectively represent a methyl group, phenyl
group, vinyl group, 3-glycidoxypropyl group, and
2-(3,4-epoxycyclohexyl) ethyl group; x1, x2, x3, and x4 are
respectively positive numbers; and the total of x1, x2, x3, and x4
in one molecule is 1.
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MeEpSiO.sub.2/2-
).sub.x3(PhSiO.sub.3/2).sub.x4
(Me.sub.2ViSiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MeEpSiO.sub.2-
/2).sub.x3(PhSiO.sub.3/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MeEpSiO.sub.2/2-
).sub.x3(MeSiO.sub.3/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(MeEpSiO.sub.2/2).sub.x2(PhSiO.sub.3/2).sub.-
x3
(Me.sub.3SiO.sub.1/2).sub.x1(MeEpSiO.sub.2/2).sub.x2(MeSiO.sub.3/2).sub.-
x3(PhSiO.sub.3/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MeEpSiO.sub.2/2-
).sub.x3
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MePhSiO.sub.2/2-
).sub.x3(MeEpSiO.sub.2/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(MePhSiO.sub.2/2).sub.x2(MeEpSiO.sub.2/2).su-
b.x3
(Me.sub.3SiO.sub.1/2).sub.x1(Ph.sub.2SiO.sub.2/2).sub.x2(MeEpSiO.sub.2/2-
).sub.x3
(Me.sub.2SiO.sub.2/2).sub.x1(MeEpSiO.sub.2/2).sub.x2(PhSiO.sub.3/2).sub.-
x3
(MeEpSiO.sub.2/2).sub.x1(PhSiO.sub.3/2).sub.x2
(Me.sub.2SiO.sub.2/2).sub.x1(EpSiO.sub.3/2).sub.x2
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(EpSiO.sub.3/2).-
sub.x3(MeSiO.sub.3/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(EpSiO.sub.3/2).-
sub.x3(PhSiO.sub.3/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(EpSiO.sub.3/2).sub.x2(MeSiO.sub.3/2).sub.x3
(Me.sub.3SiO.sub.1/2).sub.x1(EpSiO.sub.3/2).sub.x2(PhSiO.sub.3/2).sub.x3
(Me.sub.2ViSiO.sub.1/2).sub.x1(EpSiO.sub.3/2).sub.x2(PhSiO.sub.3/2).sub.-
x3
(Me.sub.3SiO.sub.1/2).sub.x1(EpSiO.sub.3/2).sub.x2
(Me.sub.2ViSiO.sub.1/2).sub.x1(EpSiO.sub.3/2).sub.x2
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MeEpSiO.sub.2/2-
).sub.x3(SiO.sub.4/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(MeEpSiO.sub.2/2).sub.x2(SiO.sub.4/2).sub.x3
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(EpSiO.sub.3/2).-
sub.x3(SiO.sub.4/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MeEp'SiO.sub.2/-
2).sub.x3(PhSiO.sub.3/2).sub.x4
(Me.sub.2ViSiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MeEp'SiO.sub.-
2/2).sub.x3(PhSiO.sub.3/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MeEp'SiO.sub.2/-
2).sub.x3(MeSiO.sub.3/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(MeEp'SiO.sub.2/2).sub.x2(PhSiO.sub.3/2).sub-
.x3
(Me.sub.3SiO.sub.1/2).sub.x1(MeEp'SiO.sub.2/2).sub.x2(MeSiO.sub.3/2).sub-
.x3(PhSiO.sub.3/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MeEp'SiO.sub.2/-
2).sub.x3
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MePhSiO.sub.2/2-
).sub.x3(MeEp'SiO.sub.2/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(MePhSiO.sub.2/2).sub.x2(MeEp'SiO.sub.2/2).s-
ub.x3
(Me.sub.3SiO.sub.1/2).sub.x1(Ph.sub.2SiO.sub.2/2).sub.x2(MeEp'SiO.sub.2/-
2).sub.x3
(Me.sub.2SiO.sub.2/2).sub.x1(MeEp'SiO.sub.2/2).sub.x2(PhSiO.sub.3/2).sub-
.x3
(MeEp'SiO.sub.2/2).sub.x1(PhSiO.sub.3/2).sub.x2
(Me.sub.2SiO.sub.2/2).sub.x1(Ep'SiO.sub.3/2).sub.x2
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(Ep'SiO.sub.3/2)-
.sub.x3(MeSiO.sub.3/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(Ep'SiO.sub.3/2)-
.sub.x3(PhSiO.sub.3/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(Ep'SiO.sub.3/2).sub.x2(MeSiO.sub.3/2).sub.x-
3
(Me.sub.3SiO.sub.1/2).sub.x1(Ep'SiO.sub.3/2).sub.x2(PhSiO.sub.3/2).sub.x-
3
(Me.sub.2ViSiO.sub.1/2).sub.x1(Ep'SiO.sub.3/2).sub.x2(PhSiO.sub.3/2).sub-
.x3
(Me.sub.3SiO.sub.1/2).sub.x1(Ep'SiO.sub.3/2).sub.x2
(Me.sub.2ViSiO.sub.1/2).sub.x1(Ep'SiO.sub.3/2).sub.x2
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(MeEp'SiO.sub.2/-
2).sub.x3(SiO.sub.4/2).sub.x4
(Me.sub.3SiO.sub.1/2).sub.x1(MeEp'SiO.sub.2/2).sub.x2(SiO.sub.4/2).sub.x-
3
(Me.sub.3SiO.sub.1/2).sub.x1(Me.sub.2SiO.sub.2/2).sub.x2(Ep'SiO.sub.3/2)-
.sub.x3(SiO.sub.4/2).sub.x4
[0022] The compound of component (B) is a component for curing the
present composition by reacting with the epoxy group in component
(A). Component (B) is not particularly restricted so long as at
least two mercapto groups are provided in a molecule, but is
preferably (B1) a mercapto group-containing organopolysiloxane as
represented by the average composition formula:
Y.sub.cR.sup.2.sub.dSiO.sub.(4-c-d)/2
[0023] and/or (B2) a thiol compound having at least two mercapto
groups in a molecule.
[0024] In the formula for component (B1), Y represents at least one
type of mercapto group selected from a group consisting of a
mercaptoalkyl group and a mercaptoaryl group. Examples of the
mercaptoalkyl group include a 3-mercaptopropyl groups, a
4-mercaptobutyl group, and a 6-mercaptohexyl group. Examples of the
mercaptoaryl group include a 4-mercaptophenyl group, a
4-mercaptomethyl phenyl group, and a 4-(2-mercaptoethyl) phenyl
group. Component (B1) has at least two mercapto groups (Y) in a
molecule.
[0025] Furthermore, in the formula, R.sup.2 represents a hydrogen
atom, alkyl group with 1 to 12 carbon atoms, alkenyl group with 2
to 12 carbon atoms, aryl group with 6 to 20 carbon atoms, aralkyl
group with 7 to 20 carbon atoms, hydroxyl group, or alkoxy group
with 1 to 6 carbon atoms. Examples of the alkyl group include the
same groups as the aforementioned R.sup.1, and a methyl group is
preferred from the perspectives of economic efficiency and heat
resistance. Examples of the alkenyl group include the same groups
as the aforementioned R.sup.1, and a vinyl group, allyl group,
hexenyl group, and octenyl group are preferred from the perspective
of of economic efficiency and reactivity. Examples of the aryl
group include the same groups as the aforementioned R.sup.1, and a
phenyl group, tolyl group, and naphthyl group are preferred from
the perspective of economic efficiency. Examples of the aralkyl
group include the same groups as the aforementioned R.sup.1.
Further examples include groups where a portion or all of the
hydrogen atoms bonded to the alkyl group, alkenyl group, aryl
group, or aralkyl group are substituted by a chlorine atom, bromine
atom, or other halogen atom. Examples of the alkoxy group include
the same groups as the aforementioned R.sup.1. R.sup.2 may have two
or more types of the aforementioned groups.
[0026] Furthermore, in the formula, "c" is a number that indicates
a ratio of mercapto groups to silicon atoms, and satisfies:
0<c<1, and preferably 0<c.ltoreq.0.6, or
0<c.ltoreq.0.4. Furthermore, in the formula, "d" is a number
that indicates a ratio of hydrogen atoms, alkyl groups with 1 to 12
carbon atoms, alkenyl groups with 2 to 12 carbon atoms, aryl groups
with 6 to 20 carbon atoms, aralkyl groups with 7 to 20 carbon
atoms, hydroxyl groups, or alkoxy groups with 1 to 6 carbon atoms
with regard to silicon atoms, and satisfies: 0<d<3. However,
the total of "c" and "d" is a number that satisfies
0.8<c+d<3, and preferably 1<c+d.ltoreq.2.5, or
1<c+d.ltoreq.2.3. This is because when "c" is a number within
the aforementioned range, the curability of the obtained curable
organopolysiloxane composition at a relatively low temperature is
favorable, and the mechanical strength of the obtained cured
product is favorable. Furthermore, use when "d" is a number within
the aforementioned range, the mechanical strength of a cured
product improves. In addition, when the total of "c" and "d" is a
number within the aforementioned range, the curability of the
obtained curable organopolysiloxane composition at a relatively low
temperature is favorable, and the mechanical strength of the
obtained cured product is favorable.
[0027] The molecular weight of component (B1) is not particularly
restricted, but the weight average molecular weight measured by gel
permeation chromatography is preferably 500 or more and 50,000 or
less. This is because when the weight average molecular weight of
component (B1) is equal to or greater than the lower limit of the
aforementioned range, the mechanical properties of the obtained
cured product are favorable, and when equal to or lower than the
upper limit of the aforementioned range, the curing rate of the
obtained curable organopolysiloxane composition improves.
[0028] Examples of component (B1) include one type or a mixture of
two or more types of an organopolysiloxane as represented by the
following average unit formulas. Note that in the formulas, Me, Ph,
Vi, and Thi respectively represent a methyl group, phenyl group,
vinyl group, and 3-mercaptopropyl group; y1, y2, y3, and y4 are
respectively positive numbers; and the total of y1, y2, y3, and y4
in a molecule is 1.
(Me.sub.3SiO.sub.1/2).sub.y1(Me.sub.2SiO.sub.2/2).sub.y2(MeThiSiO.sub.2/-
2).sub.y3(PhSiO.sub.3/2).sub.y4
(Me.sub.2ViSiO.sub.1/2).sub.y1(Me.sub.2SiO.sub.2/2).sub.y2(MeThiSiO.sub.-
2/2).sub.y3(PhSiO.sub.3/2).sub.y4
(Me.sub.3SiO.sub.1/2).sub.y1(Me.sub.2SiO.sub.2/2).sub.y2(MeThiSiO.sub.2/-
2).sub.y3(MeSiO.sub.3/2).sub.y4
(Me.sub.3SiO.sub.1/2).sub.y1(MeThiSiO.sub.2/2).sub.y2(PhSiO.sub.3/2).sub-
.y3
(Me.sub.3SiO.sub.1/2).sub.y1(MeThiSiO.sub.2/2).sub.y2(MeSiO.sub.3/2).sub-
.y3(PhSiO.sub.3/2).sub.y4
(Me.sub.3SiO.sub.1/2).sub.y1(Me.sub.2SiO.sub.2/2).sub.y2(MeThiSiO.sub.2/-
2).sub.y3
(Me.sub.3SiO.sub.1/2).sub.y1(Me.sub.2SiO.sub.2/2).sub.y2(MePhSiO.sub.2/2-
).sub.y3(MeThiSiO.sub.2/2).sub.y4
(Me.sub.3SiO.sub.1/2).sub.y1(MePhSiO.sub.2/2).sub.y2(MeThiSiO.sub.2/2).s-
ub.y3
(Me.sub.3SiO.sub.1/2).sub.y1(Ph.sub.2SiO.sub.2/2).sub.y2(MeThiSiO.sub.2/-
2).sub.y3
(Me.sub.2SiO.sub.2/2).sub.y1(MeThiSiO.sub.2/2).sub.y2(PhSiO.sub.3/2).sub-
.y3
(Me.sub.2SiO.sub.2/2).sub.y1(ThiSiO.sub.3/2).sub.y2
(Me.sub.3SiO.sub.1/2).sub.y1(Me.sub.2SiO.sub.2/2).sub.y2(ThiSiO.sub.3/2)-
.sub.y3(MeSiO.sub.3/2).sub.y4
(Me.sub.3SiO.sub.1/2).sub.y1(Me.sub.2SiO.sub.2/2).sub.y2(ThiSiO.sub.3/2)-
.sub.y3(PhSiO.sub.3/2).sub.y4
(Me.sub.3SiO.sub.1/2).sub.y1(ThiSiO.sub.3/2).sub.y2(MeSiO.sub.3/2).sub.y-
3
(Me.sub.3SiO.sub.1/2).sub.y1(ThiSiO.sub.3/2).sub.y2(PhSiO.sub.3/2).sub.y-
3
(Me.sub.2ViSiO.sub.1/2).sub.y1(ThiSiO.sub.3/2).sub.y2(PhSiO.sub.3/2).sub-
.y3
(Me.sub.3SiO.sub.1/2).sub.y1(ThiSiO.sub.3/2).sub.y2
(Me.sub.2ViSiO.sub.1/2).sub.y1(ThiSiO.sub.3/2).sub.y2
(Me.sub.3SiO.sub.1/2).sub.y1(Me.sub.2SiO.sub.2/2).sub.y2(MeThiSiO.sub.2/-
2).sub.y3(SiO.sub.4/2).sub.y4
(Me.sub.3SiO.sub.1/2).sub.y1(MeThiSiO.sub.2/2).sub.y2(SiO.sub.4/2).sub.y-
3
(Me.sub.3SiO.sub.1/2).sub.y1(Me.sub.2SiO.sub.2/2).sub.y2(ThiSiO.sub.3/2)-
.sub.y3(SiO.sub.4/2).sub.y4
[0029] On the other hand, the thiol compound of (B2) is not
particularly restricted so long as at least two mercapto groups are
provided in a molecule, and examples include:
trimethylolpropane-tris(3-mercaptopropionate),
trimethylolpropane-tris(3-mercaptobutyrate),
trimethylolethane-tris(3-mercaptobutyrate),
pentaerythritol-tetrakis(3-mercaptopropionate), tetraethylene
glylcol-bis(3-mercaptopropionate),
dipentaerythritol-hexakis(3-mercaptopropionate),
pentaerythritol-tetrakis(3-mercaptobutyrate),
1,4-bis(3-mercaptobutyryloxy) butane, and other ester compounds
between mercaptocarboxylic acids and polyhydric alcohols; ethane
dithiol, propane dithiol, hexamethylene dithiol, decamethylene
dithiol, 3,6-dioxa-1,8-octane dithiol, 1,4-benzene dithiol,
toluene-3,4-dithiol, xylylene dithiol, and other aliphatic or
aromatic thiol compounds;
1,3,5-tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, and
1,3,5-tris[(3-mercaptobutyryloxy)-ethyl]-isocyanurate; and mixtures
of two or more types thereof.
[0030] The molecular weight of the thiol compound is not
particularly restricted, but is preferably within a range of 200 to
2,000, within a range of 300 to 1,500, or within a range of 400 to
1,500. This is because when the molecular weight is equal to or
greater than the lower limit of the aforementioned range, the
volatility of the thiol compound itself is reduced, and problems
with odor are reduced, and on the other hand, when the molecular
weight is equal to or lower than the upper limit of the
aforementioned range, solubility with regard to component (A)
improves.
[0031] In the present composition, the content amount of component
(B) is an amount where the mercapto groups in the component are
within a range of 0.3 to 3 mol, and preferably within a range of
0.5 to 2 mols, or within a range of 0.8 to 1.5 mols per 1 mol of
the epoxy groups in component (A). This is because when the content
amount of component (B) is equal to or greater than the lower limit
of the aforementioned range, the obtained curable
organopolysiloxane composition is sufficiently cured, and on the
other hand, when the content amount is equal to or lower than the
upper limit of the aforementioned range, the mechanical strength of
the obtained cured product improves.
[0032] Component (C) is a component for promoting curing of the
present composition at a low temperature, and is an amine compound
that does not have a N--H bond and/or a phosphine compound that
does not have a P--H bond.
[0033] Examples of the amine compound include triethylamine,
tri-n-propylamine, tri-n-butylamine, tri-i-butylamine,
tri-n-hexylamine, tri-n-octylamine, triphenylamine,
N,N-dimethylaniline, N,N-diethylaniline, dimethyl cyclohexylamine,
diethyl cyclohexylamine, 1-methylpiperidine,
4-hydroxy-1-methylpiperidine, 4-methylmorpholine, pyridine,
4-dimethyl aminopyridine (DMAP), N,N'-dimethyl piperazine,
1,3,5-trimethyl hexahydro-1,3,5-triazine,
2,6-dimethyl-2,6-diazaheptane,
2,6,10-trimethyl-2,6,10-triazaundecane, bis(2-dimethyl aminoethyl)
ether, 1-(2-dimethyl aminoethyl)-4-methyl piperazine,
tris[2-dimethylamino)ethyl]amine, 2,4,6-tris(dimethyl aminomethyl)
phenol, and other noncylic and cyclic tertiary amine compounds; and
1,5-diazabicyclo[4.3.0] nonene (DBN), 1,8-diazabicyclo[5.4.0]
undecene (DBU), 1,4-diazabicyclo[2.2.2] octane (DABCO),
quinuclidine, and other bicyclic tertiary amine compounds.
[0034] Furthermore, examples of the phosphine compound include
triphenyl phosphine, triorthotolyl phosphine, triparatolyl
phosphine, tris(paramethoxy phenyl) phosphine, diphenyl cyclohexyl
phosphine, tricyclohexyl phosphine, triethyl phosphine, tripropyl
phosphine, tri-n-butyl phosphine, tri-t-butyl phosphine,
tri-n-hexylphosphine, and tri-n-octyl phosphine.
[0035] Component (C) is preferably a tertiary amine compound, which
may be used independently, or used by mixing at least two types. By
appropriately selecting component (C), the bath life of the curable
organopolysiloxane composition of the present invention can be
adjusted.
[0036] The content amount of component (C) is within a range of
0.01 to 10 mass % per the total amount of components (A) through
(C). This is because when the amount of component (C) is equal to
or greater than the lower limit of the aforementioned range, a
curing reaction of the obtained composition is promoted, and on the
other hand, when the amount is equal to or lower than the upper
limit of the aforementioned range, an obtained cured product is
difficult to color even by aging. In the present composition, by
appropriately selecting the content amount of component (C), the
bath life of the present composition can be adjusted.
[0037] The present composition can be provided for use without a
solvent, but may contain (D) an organic solvent as necessary if
reducing the viscosity of the present composition or forming a
cured product on a thin film is desired. The organic solvent is not
particularly restricted so long as curing of the present
composition is not inhibited, and the entire composition can
uniformly dissolve. The organic solvent preferably has a boiling
point that is 70.degree. C. or higher and lower than 200.degree.
C., and specific examples include: i-propyl alcohol, t-butyl
alcohol, cyclohexanol, ethyl acetate, propyl acetate, butyl
acetate, cyclohexanone, methyl ethyl ketone, methyl isobutyl
ketone, toluene, xylene, methylene, 1,4-dioxane, dibutyl ether,
anisole, 4-methyl anisole, ethyl benzene, ethoxy benzene, ethylene
glycol, ethylene glycol dimethyl ether, ethylene glycol diethyl
ether, 2-methoxy ethanol (ethylene glycol monomethyl ether),
diethylene glycol dimethyl ether, diethylene glycol monomethyl
ether, 1-methoxy-2-propyl acetate, 1-ethoxy-2-propyl acetate,
octamethyl cyclotetrasiloxane, hexamethyl disiloxane, and other
nonhalogenated solvents; 1,1,2-trichlorethane, chlorobenzene, and
other halogenated solvents; and mixtures of two or more types
thereof.
[0038] In the present composition, the amount of the organic
solvent is not particularly restricted, but is within a range of 0
to 3,000 parts by mass, or preferably within a range of 0 to 1,000
parts by mass per a total of 100 parts by mass of components (A)
through (C).
[0039] The viscosity at 25.degree. C. of the present composition is
not particularly restricted, but is preferably within a range of 10
to 100,000 mPas, or within a range of 10 to 10,000 mPas.
Furthermore, the organic solvent can be added to the present
composition to adjust the viscosity to be within the aforementioned
viscosity range.
[0040] The present composition can contain conventionally known
additives such as: fumed silica, crystalline silica, fused silica,
wet silica, titanium oxide, zinc oxide, iron oxide, and other metal
oxide fine powders; vinyl triethoxysilane, allyl trimethoxysilane,
allyl triethoxysilane, 3-glycidoxy propyl trimethoxysilane,
3-methacryloxy propyl trimethoxysilane, and other adhesive
imparting agents; and nitrides, sulfides, and other inorganic
fillers; pigments; heat resistance improving agents; and the like,
as components other than the aforementioned as necessary, so long
as an object of the present invention is not impaired.
[0041] The present composition can be prepared by uniformly mixing
components (A) through (C), and if necessary, other optional
components thereof. When preparing the present composition, the
components can be mixed at ambient temperature using various
stirrers or kneaders, and if the composition is one which is not
easily cured during mixing, mixing may be performed under heat.
Furthermore, the order of adding the components is not particularly
restricted, and mixing is possible in an arbitrary order.
[0042] Curing of the present composition advances even at a
relatively low temperature of -5 to 30.degree. C. Note that curing
can be promoted by heating. The time required for a curing reaction
is dependent on the types of components (A) through (C), but is
generally within 24 hours at a relatively low temperature.
[0043] A cured product of the present invention is formed by curing
the aforementioned curable organopolysiloxane composition. The form
of the cured product is not particularly restricted, and examples
include sheets, films, and tapes.
[0044] The present composition can be coated onto a film substrate,
tape substrate, or sheet substrate and then cured at -5 to
30.degree. C. to form a cured film on a surface of the substrate.
The thickness of the cured film is not particularly restricted, but
is preferably 10 to 500 .mu.m or 50 to 100 .mu.m.
[0045] Curing can advance even at a relatively low temperature, and
therefore, the present composition can be applied to coating of a
substrate with inferior heat resistance. Examples of a coating
method of the present composition include gravure coating, offset
coating, offset gravure, roll coating, reverse roll coating, air
knife coating, curtain coating, and comma coating. Furthermore,
examples of the type of substrate include paperboards, cardboard
paper, clay coated paper, and polyolefin laminated paper, and
particularly, polyethylene laminated paper, synthetic resin
film/sheet/coating films, natural fiber materials, synthetic fiber
materials, artificial leather materials, metal foils, metal sheets,
and concrete. The synthetic resin film/sheet/coating films are
particularly preferred. For a multilayer coating film, the present
composition is generally coated onto a coating film made from an
epoxy resin, acrylic resin, urethane resin, or the like.
EXAMPLES
[0046] The curable organopolysiloxane composition, cured product
thereof, and method for forming a cured film of the present
invention are described in detail using examples. In the formulas,
Me, Ph, Ep, and Thi respectively represent a methyl group, phenyl
group, 3-glycidoxypropyl group, and 3-mercaptopropyl group. Note
that in the examples, the viscosity, weight average molecular
weight, epoxy group equivalent, and mercapto group equivalent were
measured as described below.
[Viscosity]
[0047] The viscosity at 25.degree. C. was measured using a
rotational viscometer VG-DA manufactured by Shibaura System Co.,
Ltd.
[Weight Average Molecular Weight]
[0048] The weight average molecular weight calculated as standard
polystyrene was determined by gel permeation chromatography using a
RI detector.
[Epoxy Equivalent and Mercapto Equivalent]
[0049] The epoxy equivalent (g/mol) and mercapto equivalent (g/mol)
of the organopolysiloxane were determined from the structure
identified by nuclear magnetic resonance spectroscopy.
Synthesis Example 1
Preparation of an Epoxy Group-Containing Organopolysiloxane
[0050] An amount of 341 g of a hydrolysis and condensation reaction
product (weight average molecular weight: 1,000, silanol group
content: 8.0 wt %) of phenyl trichlorosilane, 528 g of
3-glycidoxypropyl methyl dimethoxysilane, 517 g of
dimethylpolysiloxane capped at both molecular chain ends with
trimethyl siloxy groups and having a dynamic viscosity at
25.degree. C. of 5 mm.sup.2/s, and 183 g of toluene were inserted
into a reactor provided with a stirring device, thermometer, reflux
tube, and dripping funnel, and then heated to 50.degree. C. and
stirred. Thereafter, a mixture of 2.5 g of cesium hydroxide and
43.2 g of water was gradually added dropwise from the dripping
funnel. After the dropwise addition was completed, the mixture was
heated and refluxed for one hour. The produced methanol and excess
water were removed by azeotropic dehydration and then a reaction
was performed for eight hours under a toluene reflux. After
cooling, the mixture was neutralized by acetic acid, and heated
under reduced pressure to distill away the toluene and low-boiling
components, and the neutralized salt was filtered to obtain a
yellowish brown transparent liquid with a viscosity of 270 mPas.
The liquid had a weight average molecular weight of 4,100, and an
epoxy equivalence of 530 g/mol, and was confirmed by
.sup.13C-nuclear magnetic resonance spectroscopy to be an epoxy
group-containing organopolysiloxane represented by the average unit
formula:
(Me.sub.3SiO.sub.1/2).sub.0.12(Me.sub.2SiO.sub.2/2).sub.0.45(EpMeSiO.sub-
.2/2).sub.0.21(PhSiO.sub.3/2).sub.0.22,
and the average composition formula:
Ep.sub.0.21Me.sub.1.47Ph.sub.0.22SiO.sub.1.05.
[0051] The content of hydroxyl groups, methoxy groups, or other
alkoxy groups was less than 1 wt %.
Synthesis Example 2
Preparation of a Mercapto Group-Containing Organopolysiloxane
[0052] An amount of 1,374 g of 3-mercaptopropyl trimethoxysilane,
1,680 g of dimethyl dimethoxysilane, and 1.18 g of trifluoromethane
sulfonic acid were inserted into a reactor provided with a stirring
device, thermometer, reflux tube, and dripping funnel, and stirred,
after which 882 g of ion exchanged water was added dropwise at room
temperature. After stirring for one hour under a methanol reflux,
calcium carbonate and cyclohexane were added, and the produced
methanol and unreacted water were removed by azeotropic
dehydration. The remaining low-boiling points material was removed
under reduced pressure, and then the solid content was filtered to
obtain a colorless transparent liquid with a viscosity of 560 mPas.
The liquid had a weight average molecular weight of 4,000, and a
mercapto equivalent of 260 g/mol, and was confirmed by
.sup.13C-nuclear magnetic resonance spectroscopy to be a mercapto
group-containing organopolysiloxane represented by the average unit
formula:
(Me.sub.2SiO.sub.2/2).sub.0.65(ThiSiO.sub.3/2).sub.0.35,
and the average composition formula:
Thi.sub.0.35Me.sub.1.30SiO.sub.1.18.
Examples 1 to 9 and Comparative Examples 1 to 3
[0053] Solvent-free type curable organopolysiloxane compositions
were prepared in with the compositions shown in Tables 1 and 2
using the following components. Note that in the curable
organopolysiloxane composition, the amount was adjusted such that
the content amount of mercapto groups in component (B) was 1 mol
per 1 mol of epoxy groups in component (A).
[0054] The following component was used as component (A).
[0055] (a-1): Epoxy group-containing organopolysiloxane prepared in
Synthesis Example 1
[0056] The following components were used as component (B).
[0057] (b-1): Mercapto group-containing organopolysiloxane prepared
in Synthesis Example 2
[0058] (b-2): Pentaerythritol-tetrakis(3-mercaptobutyrate) (Karenz
MT.RTM.PE1 manufactured by Showa Denko KK)
[0059] The following components were used as component (C).
[0060] (c-1): 2,4,6-tris(dimethylaminomethyl) phenol
[0061] (c-2): 2,6-dimethyl-2,6-diazaheptane
[0062] (c-3): 1,8-diazabicyclo[5,4,0] undecene
[0063] (c-4): 1,4-diazabicyclo[2,2,2] octane
[0064] (c-5): 1-(2-dimethyl aminoethyl)-4-methyl piperazine
[0065] (c-6): 2,6,10-trimethyl-2,6,10-triazaundecane
[0066] The following component was used as an amino
group-containing organopolysiloxane.
[0067] (e-1): 3055 resin manufactured by Dow Corning Toray Co.,
Ltd. (Viscosity: 3,000 mPas, amino equivalence=500 g/mol)
[0068] The curable organopolysiloxane composition was evaluated as
follows.
[Appearance]
[0069] The curable organopolysiloxane composition was prepared, and
then the appearance thereof was visually observed.
[Curability]
[0070] The curable organopolysiloxane composition was maintained at
25.degree. C. in a glass bottle or on an aluminum dish, the time
until fluidity was lost or the composition ceased to adhere to a
finger (gelling time) was determined, and the curability was
evaluated as follows.
[0071] : Gelling time at 25.degree. C. is within 6 hours.
[0072] : Gelling time at 25.degree. C. exceeds 6 hours, but is
within 12 hours.
[0073] : Gelling time at 25.degree. C. exceeds 12 hours, but is
within 24 hours.
[0074] .DELTA.: Gelling time at 25.degree. C. exceeds 24 hours, but
is within 48 hours.
[0075] .times.: Uncured even at 48 hours at 25.degree. C.
[0076] The curability at -2.degree. C. was evaluated as follows for
a composition cured within 24 hours at 25.degree. C.
[0077] : Gelling time at -2.degree. C. is within 6 hours.
[0078] : Gelling time at -2.degree. C. exceeds 6 hours, but is
within 12 hours.
[0079] : Gelling time at -2.degree. C. exceeds 12 hours, but is
within 24 hours.
[0080] .DELTA.: Gelling time at -2.degree. C. exceeds 24 hours, but
is within 48 hours.
[0081] .times.: Uncured even at 48 hours at -2.degree. C.
TABLE-US-00001 TABLE 1 Category Present invention Item Example 1
Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example
8 Example 9 Composition Component (a-1) 2.0 2.0 2.0 2.0 2.0 2.0 2.0
2.0 2.0 of Curable Component (b-1) -- -- -- -- -- -- 1.057 -- --
Organopolysiloxane Component (b-2) 0.514 0.514 0.514 0.514 0.514
0.514 -- 0.272 1.090 Composition Component (c-1) 0.073 -- -- -- --
-- -- -- -- (parts by mass) Component (c-2) -- 0.073 -- -- -- --
0.151 0.039 0.156 Component (c-3) -- -- 0.073 -- -- -- -- -- --
Component (c-4) -- -- -- 0.073 -- -- -- -- -- Component (c-5) -- --
-- -- 0.073 -- -- -- -- Component (c-6) -- -- -- -- -- 0.073 -- --
-- Appearance Trans- Trans- Trans- Trans- Trans- Trans- Trans-
Trans- Trans- parent parent parent parent parent parent parent
parent parent Curability at 25.degree. C. Curability at -2.degree.
C.
TABLE-US-00002 TABLE 2 Category Comparative Examples Com- parative
Comparative Comparative Item Example 1 Example 2 Example 3
Composition Component (a-1) 2.0 2.0 1.5 of Curable Component (b-2)
0.514 -- -- Organopoly- Component (c-6) -- 0.073 -- siloxane
Component (e-1) -- -- 1.489 Composition (parts by mass) Appearance
Turbid Transparent Transparent Curability at 25.degree. C. x x x
Curability at -2.degree. C. -- -- --
[0082] Based on the results of Examples 1 through 9, in the curable
organopolysiloxane composition of the present invention, it is
clear that regardless of component (B), curing at 25.degree. C.
proceeded quickly, and curing at -2.degree. C. also proceeded
quickly. On the other hand, based on the results of Comparative
Examples 1 and 2, the curable organopolysiloxane compositions not
having either of component (B) or component (C) were confirmed to
not cure or to cure very slowly. Based on the results of
Comparative Example 3, the curable organopolysiloxane composition
containing an epoxy group-containing organopolysiloxane and an
amino group-containing organopolysiloxane was confirmed to cure
slowly.
Examples 10 and 11 and Comparative Example 4
[0083] Solvent type curable organopolysiloxane compositions were
prepared with the compositions shown in Table 3 using the
aforementioned components and following component. Note that in the
curable organopolysiloxane composition, the content amounts were
adjusted such that amount of mercapto groups in component (B) was 1
mol per 1 mol of epoxy groups in component (A).
[0084] The following component was used as component (D).
[0085] (d-1): Ethyl acetate (manufactured Wako Pure Chemical
Industries, Ltd.)
[0086] The curable organopolysiloxane composition was evaluated as
follows.
[Curability]
[0087] The curability of the curable organopolysiloxane composition
was evaluated as described above.
[Bonding]
[0088] The curable organopolysiloxane composition was coated by
flow coating onto a glass plate, dried and cured for one day at
room temperature, and then dried and cured further for two hours at
70.degree. C. Bonding of the cure film on the glass plate was
evaluated by a cross-cut test (JIS K5400). The results of the
evaluation are indicated by ".smallcircle." when the cured film did
not peel, and by ".times." when the cured film peeled.
TABLE-US-00003 TABLE 3 Category Comparative Present invention
Examples Example Example Comparative Item 10 11 Example 4
Composition of Component (a-1) 0.5 0.5 0.5 Curable Component (b-1)
0.26 -- -- Organopoly- Component (b-2) -- 0.13 -- siloxane
Component (c-6) 0.04 0.02 -- Composition Component (e-1) -- --
0.496 (parts by mass) Component (d-1) 3.06 2.51 2.00 Curability at
25.degree. C. .DELTA. Curability at -2.degree. C. .DELTA. x Bonding
.smallcircle. .smallcircle. .smallcircle.
[0089] Based on the results of Examples 10 and 11, with the curable
organopolysiloxane composition of the present invention, regardless
of component (B), curing at 25.degree. C. was confirmed to occur
quickly, curing at -2.degree. C. was also confirmed to occur
quickly, and bonding of the obtained cured film was confirmed to be
favorable. On the other hand, based on the results of Comparative
Example 4, the curable organopolysiloxane composition made from an
epoxy group-containing organopolysiloxane and an amino
group-containing organopolysiloxane was confirmed to cure slowly at
a relatively low temperature.
INDUSTRIAL APPLICABILITY
[0090] The curable organopolysiloxane composition of the present
invention has favorable curability even at relatively low
temperatures, and forms a cured film with excellent bonding with
regard to an article to be coated, and therefore is favorable as a
coating composition for coating an article to be coated which has
inferior heat resistance, or coating a structure on which the use
of heating means is difficult.
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